Turbines, what turbines - that would be far more interesting than the standard electric motors these guys are using. Hang on, why don't we just go straight into jet propulsion for tunnels?!
BTW, from what I heard it was one of those 'tunnel owners' who not only dreamt up the idea of ironing boards and guitars, but he then went and took the piccies as well. These guys are so irresponsible. As you suggest, if that can get a guitar or ironing board through those tiny spaces into the motors, they could ruin the fun for all of us.
Come on guys, keep it sensible, avoid all potential opportunity of doing something different for a laugh and grow up.
And to all us jumpers, just stay on the ground, we could damage ourseves up there.
Happy Christmas